That's not accurate. Go buy an MP3 from Bandcamp, you own the mp3 (it's a merchandise transaction, not a license, it's very explicit in the terms of service) -- you don't own a license to the mp3, you own the actual mp3 (same as you would own a CD). The same is true of several other mp3 stores and a handful of ebook providers, as well as when you buy ebooks directly from the author (quick example: https://melissafmiller.com/how-and-why-to-buy-ebooks-direct-from-me-and-other-authors/).
Owning the CD doesn't allow you to make derivative works as owning the CD doesn't make you the copyright holder, just like owning the mp3 doesn't actually mean you're the copyright holder, and I'm not making any argument otherwise (referring to your "legally permitted to do whatever you want" comment) -- but you absolutely can buy mp3s and ebooks and not license them.
DRM is an entirely separate issue and not relevant here as none of what I'm referring to relates to non-DRM protected licensed content.
I'm not trying to be a jerk here, but you saying it over and over and offering no proof or corroborating evidence for your claims isn't furthering the discussion. I've provided two examples of cases where purchasing a file constitutes ownership and not a license, one where purchasing an MP3 constitutes full ownership of the MP3 via the terms of service, and one where purchasing an eBook constitutes full ownership of the ebook. According to you this is impossible, but I've provided two clear examples where it is, in fact, possible.
I am interested in hearing why you believe what you believe and what evidence you can present that supports your beliefs, but if all you can do is restate that you say it's x/y/z without any legal standing it and without anything that explains how the terms of service I provided are incorrect or unenforcable (e.g., can you provide me any previous situation in case law where terms of service expressly disclose an mp3 or ebook purchase as a merchandise transaction, but then treat as a revocable license?), I'm not sure where we can go from here. I appreciate your willingness to have the discussion but I'm not here to take someone's word without any corroborating evidence.
I think that a lot of people think what you think, and I think a lot of people think that because the majority of places online only allow purchases as licenses, but just because 85% or 90% of places you go online sell you a license to an mp3 or an ebook doesn't mean that other places don't exist where you can buy the mp3 or ebook outright. Further, I've done a lot of digging and I cannot find any case law that supports your claim that it's not possible to "own" a file. Authors own manuscripts they write on their computer and can seek civil or criminal penalties when those files are stolen, musicians own the raw files they make of their music and can do the same, etc.